question about devices handling all the NEW LAND

The whole town screenshot would most likely be affected.

As for gameplay it gives you more room to spread out or re-arrange things. The real issue for that is the item limit increase. It'd be the extra things that have the bigger effect rather than the extra land.
That's why the zoom out only shows so much at once though, to limit what it needs to display and run, so it may not be much of an issue after all.